Various methods are known in the art to remove an undesired gaseous component from a process gas stream. In processes used for industrial separation of acidic components such as H2S, CO2, COS and/or mercaptans from a gas stream such as flue gas, natural gas, syngas or other gas streams mainly containing nitrogen, oxygen, hydrogen, carbon monoxide and/or methane, liquid solutions comprising amine compounds or aqueous ammonia solutions are commonly used as a solvent. The acidic components are absorbed in the solvent in an absorption process, commonly performed in an absorption unit such as a packed bed column.
After removal of acidic components, the purified gas stream leaves the absorption unit for further processing or for discharge. The solvent containing the absorbed acidic components is generally heated in a heat exchanger and separated from the acidic components in a regenerator. This separation is generally referred to as “stripping”. After stripping, the solvent may be sent back to the absorption unit via a heat exchanger to reduce the temperature of the solvent entering the absorption unit. Thus, the system process comprising an absorption unit and a regenerator allows continuous operation of removal of acidic components from a gas stream.
U.S. Pat. No. 6,645,446 discloses a split-flow process for removing a gaseous component, such as CO2, from a process gas stream. The process comprises combining semi-rich solvent coming from an upper section of an absorber with semi-lean solvent from a regenerator to form a mixed solvent stream. The mixed solvent stream is subsequently fed to the lower section of the absorber.
Although various improvements of conventional gas purification technologies are known, there is an ever-existing desire to further improve these technologies, e.g. in respect of purification efficacy and energy consumption.